1. Field Technology of the Invention
The present invention relates to a structure for mounting on a circuit board a multifunctional vibrating actuator to be installed in a portable terminal equipment such as portable telephones.
2. Description of Related Art
Devices for notification of incoming calls is mounted in portable terminal equipment such as portable telephones; among these devices are multifunctional vibrating actuators that have been devised and implemented to inform users of incoming calls by means of an audible melody or buzzer or a bodily sensible vibration, and also function as a receiver speaker.
FIG. 20 shows a typical structure of a multifunctional vibrating actuator as described above (see, for example, Patent Document 1).
Patent Document 1: Japanese Patent No. 3363792 (pages 3 to 6, FIG. 1)
As shown in FIG. 20, the multifunctional vibrating actuator 100 has a flat casing with a cylindrical housing 2 that is open at both ends, with a plate-shaped cover 101 attached to the upper opening of the housing 2 and a plate-shaped bracket 3 attached to the lower opening of the housing 2. Within this casing there is provided a diaphragm 4 that produces sound waves by being vibrated at a resonant frequency in the audible range (such as 2.5 kHz) and a magnetic circuit 5 that vibrates the casing by being vibrated at a resonant frequency lower than the resonant frequency of the diaphragm 4 (such as 130 Hz). Further, there is provided a terminal seat 9 on the housing 2 to which are attached a pair of terminals 102, 103 for input to the voice coil 12 of a driver signal that drives the diaphragm 4 and/or the magnetic circuit 5.
The pair of terminals 102, 103 has left/right symmetry and the two have basically the same structure; therefore only the terminal 102 is explained here. As shown in FIG. 21, the terminal 102 comprises a strip-shaped terminal body 102a and a contact 102b that is formed by bending the strip at a right angle at the lower end of the terminal body 102a. A connector 102c is formed as a notch at the upper end of the terminal body 102a. Further, two wedges 102d, 102e with a height of about 0.1 mm project from the edges of the terminal body 102a. By this means, when the terminals 102, 103 are inserted into the terminal seat 9, the wedging action of the wedges 102d, 103e holds them firmly in the terminal seat 9.
The magnetic circuit 5 comprises a suspension 13 formed so that it can deform flexibly in the up and down direction of FIG. 20, a magnet 6, and a pole piece 7 and a yoke 8 that sandwich the magnet 6. The magnetic circuit 5 is fastened to the inner periphery of the suspension 13, and the outer periphery of the suspension 13 is attached by means of sandwiching between the housing 2 and the bracket 3. In this way, the magnetic circuit 5 is able to vibrate up and down relative to the housing 2.
The diaphragm 4, on the other hand, has a voice coil 12 attached to it, and its outer periphery is sandwiched between the housing 2 and the cover 101. A portion of the voice coil 12 is drawn outside the housing 2 and attached to the connectors 102c, 103c of the terminals 102, 103 as shown in FIG. 22, thus electrically connecting the terminals 102, 103 and the voice coil 12. In this way, the diaphragm 4 is able to vibrate up and down relative to the housing 2. The voice coil 12 is located within the electrical gap G of the magnetic circuit 5. By this means, when a driver signal is impressed on the voice coil 12, a magnetic attraction or repulsion operates between the magnetic circuit 5 and the diaphragm 4. Accordingly, by changing the frequency of the driver signal impressed on the voice coil 12, it is possible to drive vibration of the magnetic circuit 5 and/or the diaphragm 4.
In order to make the electrical connection between the terminals mentioned above and the circuit board that is installed in the portable terminal equipment, this sort of multifunctional vibrating actuator has been both mounted on the surface of the circuit board and held in place by the case of the portable terminal equipment.
In recent years, the multifunctional vibrating actuator has had to be fixed to the surface of the circuit board by means of solder reflow. That is because the components other than the multifunctional vibrating actuator—the ICs and LSIs—are mounted on the surface of the circuit board by means of solder reflow, and work efficiency is improved if the multifunctional vibrating actuator is compatible with solder reflow fixing and can be mounted to the circuit board in the same process as the other components.
The mounting of the multifunctional vibrating actuator 100 to the surface of the circuit board by means of solder reflow fixing is explained next with reference to FIGS. 23 through 25. As shown in FIG. 23, a land 104b for solder reflow fixing of the bracket 3 is formed in advance on the surface of the circuit board 14, and electrodes 104a, 105a are formed there for the solder reflow fixing of the contacts 102b, 103b of the terminals 102, 103. Then, at the time of solder reflow mounting and fixing, a cream solder (not illustrated) is applied to the land 104b and the electrodes 104a, 105a. 
Next, as shown in FIGS. 24 and 25, the multifunctional vibrating actuator 100 is positioned on the surface of the circuit board 14. It is aligned to position the bracket 3 on the land 104b and the contacts 102b, 103b, on the electrodes 104a, 105a. Then the circuit board 14 with the multifunctional vibrating actuator 100 is inserted in a reflow tank and heated to melt the solder. After heating, the circuit board 14 is removed from the reflow tank, the solder solidifies, and the multifunctional vibrating actuator 100 is fixed to the surface of the circuit board 14.